CVE-2026-107737: CWE-129: Improper Validation of Array Index in sumatrapdfreader sumatrapdf
Description
SumatraPDF is a multi-format reader for Windows. In 3.6.1 and earlier, and in pre-release 3.7.0.20369 when WebView2 is absent or cannot initialize, ParseProtoUrl() accepts the signed host component of an its:// URL and FindHtmlWindowById() uses it directly as an index into gHtmlWindows. Opening a crafted CHM through the IE fallback backend with a negative or otherwise out-of-range window identifier can cause an out-of-bounds pointer read followed by an invalid object callback dereference and process termination. No fixed version is available as of this review.
CVSS v4.0
Score 5.7medium
Affected software
sumatrapdfreader
sumatrapdf
Weaknesses
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- GitHub_M
- Date Reserved
- 2026-10-08T17:21:52.977Z
- Cvss Version
- 4.0
- State
- PUBLISHED
Threat ID: 6ac81de02cdf04f6563fadff
Added to database: 10/08/2026, 22:49:04 UTC
Last updated: 10/08/2026, 22:49:04 UTC
Views: 1
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